As a matter of course, from the nature of the equipment as a tool that suctions liquid and discharges a metered volume of liquid, it is assumed that a liquid metering dispensing device called a pipette or dispenser (hereinafter, referred to as “pipette”) as one kind of liquid volume meter can perform proper discharge.
Here, pipettes as equipment for discharging a predetermined volume of liquid have been increasingly used according to diversification of technical fields and fields of use requiring discharging of a predetermined volume of liquid. For example, in line with an expanding market in, for example, the pharmaceutical industry and biotechnology-related industries, the sales volume has reached 2,000,000 per year around the world, and even now, it is expanding at a rate of approximately 5% per year. Pipettes themselves are not so expensive, so that it is not rare at the laboratory level that one researcher possesses about 10 pipettes.
On the other hand, according to advancements in technology, higher performance of pipettes has been demanded, and assurance of performance of pipettes has also been increasingly required. Therefore, at present, for maintaining performance, about 400,000 pipettes are inspected, calibrated, and repaired per year, and it is considered that the number of pipettes targeted for maintenance will further increase.
A pipette is configured to suction and discharge a predetermined volume of liquid by a change in capacity of a cylinder portion according to actuation of a piston that is actuated inside a main body formed as a cylinder. Therefore, the suction and discharge performance of a pipette depends on maintenance of airtightness of the device around the piston portion. Considering this, devices for conducting an inspection (leakage test) of airtightness of a device required to have airtightness have been proposed as described in the Patent Documents listed below, and it is considered that performance inspections of pipettes can be conducted by using these devices.    Patent Document 1: Japanese Published Examined Patent Application No. H04-019431    Patent Document 2: Japanese Published Unexamined Patent Application No. H08-320270    Patent Document 3: Japanese Published Unexamined Patent Application No. H10-096677    Patent Document 4: Japanese Published Unexamined Patent Application No. 2005-091042    Patent Document 5: U.S. Pat. No. 5,537,880